<template>
    <div class="todo-footer" v-show="total">
        <label>
            <input type="checkbox" :checked="isAll" @change="checked($event)">
        </label>
        <span>
            <span>已完成{{doneTotal}}</span> / 全部{{total}}
        </span>
        <button class="btn btn-danger" @click="deleteAll">删除已完成任务</button>
    </div>
</template>

<script>
export default {
    name: 'MyFooter',
    props: {
        todos: {
            type: Array,
            default: () => []
        },
        allChecked: {
            type: Function
        },
        deleteAllDone: {
            type: Function
        }
    },
    computed:{
        total() {
            return this.todos.length
        },
        doneTotal() {
            return this.todos.reduce((pre, curr) => pre + (curr.done ? 1 : 0), 0)
        },
        isAll() {
            return this.doneTotal === this.total && this.total > 0
        }
    },
    methods:{
        checked(e) {
            this.allChecked(e.target.checked)
        },
        deleteAll() {
            this.deleteAllDone()
        }
    }
}
</script>

<style scoped>
/* footer 样式 */
.todo-footer {
  height: 40px;
  line-height: 40px;
  padding-left: 6px;
  margin-top: 5px;
}

.todo-footer label {
  display: inline-block;
  margin-right: 20px;
  cursor: pointer;
}

.todo-footer label input {
  position: relative;
  top: 1px;
  vertical-align: middle;
  margin-right: 5px;
}

.todo-footer button {
  float: right;
  margin-top: 5px;
}
</style>